def demo(obj):
    print("原值", obj)
    obj += obj


print("===========值传递=============")
mot = "当你经历了九重的孤独，才会成为真正的强者"
print("before", mot)
demo(mot)
print("after", mot)
print("============引用传递===========")
list1 = ['a', 'b', 'cw', 'd']
print("before", list1)
demo(list1)
print("after", list1)
